Some steam plants include a multistage condenser. In the multistage condenser, since cooling water inlet temperatures of condensers are different from each other, pressures of saturated steam generated in a process in which steam is returned to water by each condenser are different among the condensers. Accordingly, when two condensers are provided, one condenser is a high-pressure condenser, and the other condenser is a low-pressure condenser.
PTL 1 below discloses a multistage pressure condenser which includes a high-pressure condenser and a low-pressure condenser. The low-pressure condenser of the multistage pressure condenser includes a low-pressure condensate container into which low-pressure steam flows from the upper portion of the condenser, a pressure bulkhead which partitions the inside of the low-pressure condensate container into an upper space and a lower space, a heat transfer tube which is disposed in the upper space and condenses the low-pressure steam, and a tray which is disposed in the lower space. The low-pressure condenser and the high-pressure condenser are connected to each other by a steam duct through which a portion of high-pressure steam flowing into the high-pressure condenser is introduced into the lower space of the low-pressure condenser.
A plurality of through-holes which vertically penetrate are formed in the pressure bulkhead of the low-pressure condenser. Water which is condensed in the upper space flows down into the lower space through the plurality of through-holes of the pressure bulkhead. After the water is temporarily collected in the tray, the water overflows from the tray and is collected on a bottom in the lower space. While the water reaches the tray through the plurality of through-holes of the pressure bulkhead, and while the water overflows from the tray and reaches a water collection portion of the lower space, the water is subjected to high-temperature and high-pressure steam from the high-pressure condenser so as to be heated. In addition, when the water overflowing from the tray drops on the water collected on the bottom of the lower space, since a circulation flow is generated in the water collected on the bottom of the lower space, a contact ratio between the water and the high-temperature and high-pressure steam passing through the upper side of the water increases. Accordingly, with the technology disclosed in PTL 1, it is possible to increase the temperature of the water collected on the bottom of the lower space.